Hummm not really, on the device the file access rights are are bit different... For writing like high score file or configuration I suggest you to use like FILE* and write it in like the Documents directory, since the user have read & write access on it. This path will also be available on every device so its a safe location, SIO2stream is basically a variation of FILE*, yes, but accessing only the memory and do not have API to write on disk, just read...

However I take you suggestion and will add this feature on one of the upcoming tutorials...